C.B. Macpherson is an important figure in Canadian political thought. Reading his Massey Lectures, I came across this interesting analysis of labour “capacity” versus “ability”, which is related to, but not the same as, Marx’s distinction between “labour” and “labour power”:
If you take the powers of a man to be simply the strength and skill which he possesses, then when he sells the use of that strength and skill to another at its market price there is no net transfer of any of his powers to another: he gets no less than he gives.
But if you take the powers of man to be not just the strength and skill which he possesses, but his ability to use that strength and skill to produce something, the case is altogether different. For then his powers must include not only his capacity to labour (that is, his strength and skill) but also his ability to labour, his ability to use his strength and skill. I do not see how any narrower a definition of the powers of a man is consistent with his essential human quality. The power of a horse or machine may be defined as the amount of work it can do whether it is set to work or not. But a human being, to be human, must be able to use his strength and skill for purposes he has consciously formed. So the powers of a man must include his being able to put his strength and skill to work. His powers must therefore include access to something to work on, access to the land or materials or other capital without which his capacity to labour cannot become active labour and so cannot produce anything or do anything to his purpose. A man’s powers, in short, must include access to what I have called the means of labour.
If a man’s powers must include access to the means of labour, then his powers are diminished when he has less than free access to the means of labour. If he has no access, his powers are reduced to zero and he ceases to live, unless he is rescued by some dispensation form outside the competitive market. If he can get some access but cannot get it for nothing, then his powers are reduced by the amount of them he has to hand over to get the necessary access. This is exactly the situation most men are in, and necessarily so, in the capitalist market society. They must, in the nature of the system, permit a net transfer of part of their powers to those who own the means of labour.
….That such a transfer is a necessary characteristic of any capitalist market society si commonly overlooked. It is obscured by the more obvious fact about capitalism, that it has been enormously more productive than any previous system, and so has been able to afford a higher material standard for everybody than could any previous system….at least for all except the lowest one-quarter or so who are at or below the poverty line.
…[I]t is now possible, as it was not possible…to conceive of a system in which high productivity does not require the transfer of powers from non-owners. Not only is it possible to conceive of such a system; it has been conceived, and is being attempted, in the socialist third of the world. Whether or not this alternative system can be made to work as it is intended to, we have to reckon with the fact that it is in full spate, and that it is attractive to the imagination of the newly-independent underdeveloped countries as well. It is one of history’s mean tricks that the enormous advances in productivity that were made by capitalism, and could not have been made in any other way, can now possibly be taken over by those who have rejected capitalism. But history is no respecter of the past.
From The Real World of Democracy by C.B. Macpherson, the 1961 Massey Lectures. Quote taken from pages 43 to 45 of the 16th reprinting (1987), published by CBC publications in Toronto.